GERM-LINE AND EMBRYONIC EXPRESSION OF FEX, A MEMBER OF THE DROSOPHILAF-ELEMENT RETROTRANSPOSON FAMILY, IS MEDIATED BY AN INTERNAL CIS-REGULATORY CONTROL REGION
B. Kerber et al., GERM-LINE AND EMBRYONIC EXPRESSION OF FEX, A MEMBER OF THE DROSOPHILAF-ELEMENT RETROTRANSPOSON FAMILY, IS MEDIATED BY AN INTERNAL CIS-REGULATORY CONTROL REGION, Molecular and cellular biology, 16(6), 1996, pp. 2998-3007
The F elements of Drosophila melanogaster belong to the superfamily of
Long interspersed nucleotide element retrotransposons. To date, F ele
ment transcription has not been detected in flies. Here we describe th
e isolation of a member of the F-element family, termed Fex, which is
transcribed in specific cells of the female and male germ lines and in
various tissues during embryogenesis of D. melanogaster. Sequence ana
lysis revealed that this element contains two complete open reading fr
ames coding for a putative nucleic acid-binding protein and a putative
reverse transcriptase. Functional analysis of the 5' region, using ge
rm line transformation of Fex-lacZ reporter gene constructs, demonstra
tes that major aspects of tissue-specific Fex expression are controlle
d by internal cis-acting elements that lie in the putative coding regi
on of open reading frame 1. These sequences mediate dynamic gene expre
ssion in eight expression domains during embryonic and germ line devel
opment. The capacity of the cis-regulatory region of the Fex element t
o mediate such complex expression patterns is unique among members of
the long interspersed nucleotide element superfamily of retrotransposo
ns and is reminiscent of regulatory regions of developmental control g
enes.